Analyzing the Optical Density, Whiteness Index, and Mechanical Properties of Standard White Polyester Film
Product Overview
When engineers need absolute light blocking and a flawless white background, standard clear films are simply not an option. For decades, the industry has looked to high-performance white films like Lumirror E20. This pigment-filled polyester film has set the benchmark for opacity and color stability in X-ray backing, smart cards, and high-end labels. In this technical breakdown, we decode the exact properties of Lumirror E20 White PET Film and explore how modern manufacturers can achieve equivalent or even better performance.
The Core Specs: Whiteness and Opacity
What makes Lumirror E20 a standout material? It comes down to how it handles light.
- Whiteness Index: The data sheet shows a whiteness index of over 90%. This is achieved by heavily filling the PET resin with premium titanium dioxide (TiO2) pigments, ensuring a brilliant, consistent white surface that prevents yellowing over time.
- Optical Density (OD): This is the critical metric for opacity. E20 ranges from an OD of 0.76 at 38μm to 1.93 at 250μm. This means that even the thinner gauges effectively block light transmission, making it perfect for X-ray reflection sheets and digital printing.
- Mechanical Stability: Despite the heavy pigment loading, the film maintains a tensile strength of 156 to 186 MPa. It can withstand the rigors of converting, die-cutting, and thermal lamination.
Key Applications
Because of its excellent optical density and whiteness, this grade of white PET is heavily used in:
- Medical Imaging: As a reflection sheet behind X-ray films to enhance contrast.
- Card Manufacturing: As an opaque core layer for smart cards and ID cards.
- Premium Labeling: For pharmaceutical and cosmetic bottles where a solid white background is required.
- White Boards: As a durable backing for displays.
Sourcing the Right Alternative
While Lumirror E20 is an excellent product, global supply chain challenges and high brand premiums often lead buyers to look for a Lumirror E20 Alternative. The good news is that modern BOPET factories can now produce white PET films that match these exact specifications. The key is finding a manufacturer that controls the pigment dispersion evenly, avoiding streaks or pinholes.
Technical Characteristics
The following values represent the typical capabilities of our equivalent White PET Film range:
- Material: Pigment-Filled Biaxially Oriented Polyethylene Terephthalate
- Thickness Range: 38 μm up to 250 μm
- Whiteness Index: above 90 percent
- Optical Density: 0.76 (at 38um) up to 1.93 (at 250um)
- Tensile Strength: MD 156 to 186 MPa / TD 147 to 189 MPa
- Thermal Shrinkage at 150°C, 30min: MD 1.1% to 1.4% / TD 0.2% to 0.5%
- Certifications: RoHS, REACH, UL746B (RTI 105°C)
Why Choose Jinlu Film as Your Supplier
Jinlu Film is a leading manufacturer of high-opacity White PET Film. We offer a direct factory alternative to premium Japanese brands, providing the same high whiteness index and optical density at a much more competitive price. Whether you need standard rolls or custom slitting, we ensure strict batch-to-batch color consistency.
Contact us today for a factory quote, technical data, or a sample of White Opaque PET Film.
